AB1172 SHINS MUSCLE DYSFUNCTION IN FEMALE PATIENTS WITH KNEE OSTEOARTHRITIS
Authors: L. Shvets, V. Novoseletskyi, I. Shapoval, L. Perebetiuk, V. Khomenko, M. Stanislavchuk
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Knee osteoarthritis (OA) is a chronic disease known as a common source of pain and disability globally. OA is among the top 10 causes of physical disability in the elderly population. Loss of muscle mass and lower extremity muscle dysfunction are independently associated with progression of OA and reduction in health status. <h3>Objectives</h3> The investigation was aimed at studying the condition of flexor/extensor shin muscles in patients with knee OA, serum leptin concentrations and analyze correlations between them by statistical methods. <h3>Methods</h3> The study involved 71 patients with knee OA and 32 persons from the control group. There was measured the isometric strength of the flexor/extensor shin muscles and measured leptin serum levels. Muscle strength was measured by using an isokinetic device, approved by a state enterprise "Ukrainian Intellectual Property Institute" (patent #81950). All patients were performed common clinical investigations (complaints, medical history, physical examination data) laboratory, instrumental (knee joint X-ray) examinations, and statistical analysis methods were used. <h3>Results</h3> : It was established that the age of OA patients included in the study ranged from 30 to 76 years and averaged 57,60 ± 11,69 years, and 32 % of the examined patients had had the history disease from 6 to 10 years, and 90,4 % of them suffered from excessive body weight or obesity of a certain degree. The study of maximal isometric force of flexor/extensor muscles of both shins revealed a significant reduction in the muscle strength in OA patients compared with the individuals from the control group. Thus, apparently healthy individuals had the strength of shin flexor muscles (min-max) within 9,6 – 16,9 kg, while the extensors muscles showed 12,6 – 22,5 kg. The OA patients had the strength of both shin muscle groups within the range of 0,7 – 12,1 kg for the flexor group, and 3,3 – 20,3 kg for extensor muscles. At the same time, like in the control group, the strength of the extensor muscles appeared to be higher than the one of the flexors. The calculated total muscle strength (the sum of the flexor and extensor muscle strength of both limbs) in OA patients was 31,97 ± 9,2 kg, whereas in the apparently healthy persons it was 58,65 ± 6,59 kg (p &lt;0,001). The calculated specific muscle strength (the ratio of the total strength to the patient's BMI) in OA patients was 1,03 ± 0,32 kg against 2,21 ± 0,24 kg in the control group (p &lt;0,001). The above data suggest that OA patients were characterized by a decrease in specific muscle strength, not only in total muscle strength. The total force of muscles of patients in relation to healthy individuals was 1,8 times less, the specific force was less 2,2 times. Using the correlation analysis, we established that there was no correlation between the total muscle strength and OA patients` blood leptin (r = -0,05, p&gt;0,05), however, an inverse correlation between the specific force muscle and leptin concentration (r = -0,2, p = 0,09) was found. Instead, in the control group a statistically unreliable direct correlation between the total muscle strength and leptin level (r = 0,12, p&gt;0,05), and the inverse statistically significant association between the specific strength and the leptin concentration (r = -0,412, p&lt;0,05) were revealed. Such an inverse correlation undeniably suggests that the negative effect of leptin on the condition of muscle tissue and the blood elevation thereof is associated with a decrease in muscle strength. At the same time, a significantly lower coefficient of correlation between leptin concentrations and the specific strength of patients` muscles indicates that, in addition to leptin, the disease itself (OA) makes a significant contribution to the reduction of muscle strength. <h3>Conclusion</h3> Understanding the role of the flexor/extensor shin muscles dysfunction in the pathogenesis of knee OA may help to improve further management approaches. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.